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ocfs2: teach ocfs2_file_aio_write() about sparse files

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Unfortunately, ocfs2 can no longer make use of generic_file_aio_write_nlock()
because allocating writes will require zeroing of pages adjacent to the I/O
for cluster sizes greater than page size.

Implement a custom file write here, which can order page locks for zeroing.
This also has the advantage that cluster locks can easily be ordered outside
of the page locks.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Mark Fasheh 2007-02-09 20:24:12 -08:00
parent 89488984ac
commit 9517bac6cc
7 changed files with 1077 additions and 58 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

679
fs/ocfs2/aops.c
View file

@ -24,6 +24,7 @@
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <asm/byteorder.h>
#include <linux/swap.h>
#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>
@ -37,6 +38,7 @@
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "suballoc.h"
#include "super.h"
#include "symlink.h"
@ -645,23 +647,27 @@ static ssize_t ocfs2_direct_IO(int rw,
mlog_entry_void();
/*
* We get PR data locks even for O_DIRECT. This allows
* concurrent O_DIRECT I/O but doesn't let O_DIRECT with
* extending and buffered zeroing writes race. If they did
* race then the buffered zeroing could be written back after
* the O_DIRECT I/O. It's one thing to tell people not to mix
* buffered and O_DIRECT writes, but expecting them to
* understand that file extension is also an implicit buffered
* write is too much. By getting the PR we force writeback of
* the buffered zeroing before proceeding.
*/
ret = ocfs2_data_lock(inode, 0);
if (ret < 0) {
mlog_errno(ret);
goto out;
if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
/*
* We get PR data locks even for O_DIRECT. This
* allows concurrent O_DIRECT I/O but doesn't let
* O_DIRECT with extending and buffered zeroing writes
* race. If they did race then the buffered zeroing
* could be written back after the O_DIRECT I/O. It's
* one thing to tell people not to mix buffered and
* O_DIRECT writes, but expecting them to understand
* that file extension is also an implicit buffered
* write is too much. By getting the PR we force
* writeback of the buffered zeroing before
* proceeding.
*/
ret = ocfs2_data_lock(inode, 0);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
ocfs2_data_unlock(inode, 0);
}
ocfs2_data_unlock(inode, 0);
ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
inode->i_sb->s_bdev, iov, offset,
@ -673,6 +679,647 @@ out:
return ret;
}
static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
u32 cpos,
unsigned int *start,
unsigned int *end)
{
unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
unsigned int cpp;
cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
cluster_start = cpos % cpp;
cluster_start = cluster_start << osb->s_clustersize_bits;
cluster_end = cluster_start + osb->s_clustersize;
}
BUG_ON(cluster_start > PAGE_SIZE);
BUG_ON(cluster_end > PAGE_SIZE);
if (start)
*start = cluster_start;
if (end)
*end = cluster_end;
}
/*
* 'from' and 'to' are the region in the page to avoid zeroing.
*
* If pagesize > clustersize, this function will avoid zeroing outside
* of the cluster boundary.
*
* from == to == 0 is code for "zero the entire cluster region"
*/
static void ocfs2_clear_page_regions(struct page *page,
struct ocfs2_super *osb, u32 cpos,
unsigned from, unsigned to)
{
void *kaddr;
unsigned int cluster_start, cluster_end;
ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
kaddr = kmap_atomic(page, KM_USER0);
if (from || to) {
if (from > cluster_start)
memset(kaddr + cluster_start, 0, from - cluster_start);
if (to < cluster_end)
memset(kaddr + to, 0, cluster_end - to);
} else {
memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
}
kunmap_atomic(kaddr, KM_USER0);
}
/*
* Some of this taken from block_prepare_write(). We already have our
* mapping by now though, and the entire write will be allocating or
* it won't, so not much need to use BH_New.
*
* This will also skip zeroing, which is handled externally.
*/
static int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
struct inode *inode, unsigned int from,
unsigned int to, int new)
{
int ret = 0;
struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
unsigned int block_end, block_start;
unsigned int bsize = 1 << inode->i_blkbits;
if (!page_has_buffers(page))
create_empty_buffers(page, bsize, 0);
head = page_buffers(page);
for (bh = head, block_start = 0; bh != head || !block_start;
bh = bh->b_this_page, block_start += bsize) {
block_end = block_start + bsize;
/*
* Ignore blocks outside of our i/o range -
* they may belong to unallocated clusters.
*/
if (block_start >= to ||
(block_start + bsize) <= from) {
if (PageUptodate(page))
set_buffer_uptodate(bh);
continue;
}
/*
* For an allocating write with cluster size >= page
* size, we always write the entire page.
*/
if (buffer_new(bh))
clear_buffer_new(bh);
if (!buffer_mapped(bh)) {
map_bh(bh, inode->i_sb, *p_blkno);
unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
}
if (PageUptodate(page)) {
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
(block_start < from || block_end > to)) {
ll_rw_block(READ, 1, &bh);
*wait_bh++=bh;
}
*p_blkno = *p_blkno + 1;
}
/*
* If we issued read requests - let them complete.
*/
while(wait_bh > wait) {
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
ret = -EIO;
}
if (ret == 0 || !new)
return ret;
/*
* If we get -EIO above, zero out any newly allocated blocks
* to avoid exposing stale data.
*/
bh = head;
block_start = 0;
do {
void *kaddr;
block_end = block_start + bsize;
if (block_end <= from)
goto next_bh;
if (block_start >= to)
break;
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr+block_start, 0, bh->b_size);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
next_bh:
block_start = block_end;
bh = bh->b_this_page;
} while (bh != head);
return ret;
}
/*
* This will copy user data from the iovec in the buffered write
* context.
*/
int ocfs2_map_and_write_user_data(struct inode *inode,
struct ocfs2_write_ctxt *wc, u64 *p_blkno,
unsigned int *ret_from, unsigned int *ret_to)
{
int ret;
unsigned int to, from, cluster_start, cluster_end;
unsigned long bytes, src_from;
char *dst;
struct ocfs2_buffered_write_priv *bp = wc->w_private;
const struct iovec *cur_iov = bp->b_cur_iov;
char __user *buf;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start,
&cluster_end);
buf = cur_iov->iov_base + bp->b_cur_off;
src_from = (unsigned long)buf & ~PAGE_CACHE_MASK;
from = wc->w_pos & (PAGE_CACHE_SIZE - 1);
/*
* This is a lot of comparisons, but it reads quite
* easily, which is important here.
*/
/* Stay within the src page */
bytes = PAGE_SIZE - src_from;
/* Stay within the vector */
bytes = min(bytes,
(unsigned long)(cur_iov->iov_len - bp->b_cur_off));
/* Stay within count */
bytes = min(bytes, (unsigned long)wc->w_count);
/*
* For clustersize > page size, just stay within
* target page, otherwise we have to calculate pos
* within the cluster and obey the rightmost
* boundary.
*/
if (wc->w_large_pages) {
/*
* For cluster size < page size, we have to
* calculate pos within the cluster and obey
* the rightmost boundary.
*/
bytes = min(bytes, (unsigned long)(osb->s_clustersize
- (wc->w_pos & (osb->s_clustersize - 1))));
} else {
/*
* cluster size > page size is the most common
* case - we just stay within the target page
* boundary.
*/
bytes = min(bytes, PAGE_CACHE_SIZE - from);
}
to = from + bytes;
if (wc->w_this_page_new)
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
cluster_start, cluster_end, 1);
else
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
from, to, 0);
if (ret) {
mlog_errno(ret);
goto out;
}
BUG_ON(from > PAGE_CACHE_SIZE);
BUG_ON(to > PAGE_CACHE_SIZE);
BUG_ON(from > osb->s_clustersize);
BUG_ON(to > osb->s_clustersize);
dst = kmap(wc->w_this_page);
memcpy(dst + from, bp->b_src_buf + src_from, bytes);
kunmap(wc->w_this_page);
/*
* XXX: This is slow, but simple. The caller of
* ocfs2_buffered_write_cluster() is responsible for
* passing through the iovecs, so it's difficult to
* predict what our next step is in here after our
* initial write. A future version should be pushing
* that iovec manipulation further down.
*
* By setting this, we indicate that a copy from user
* data was done, and subsequent calls for this
* cluster will skip copying more data.
*/
wc->w_finished_copy = 1;
*ret_from = from;
*ret_to = to;
out:
return bytes ? (unsigned int)bytes : ret;
}
/*
* Map, fill and write a page to disk.
*
* The work of copying data is done via callback. Newly allocated
* pages which don't take user data will be zero'd (set 'new' to
* indicate an allocating write)
*
* Returns a negative error code or the number of bytes copied into
* the page.
*/
int ocfs2_write_data_page(struct inode *inode, handle_t *handle,
u64 *p_blkno, struct page *page,
struct ocfs2_write_ctxt *wc, int new)
{
int ret, copied = 0;
unsigned int from = 0, to = 0;
unsigned int cluster_start, cluster_end;
unsigned int zero_from = 0, zero_to = 0;
ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), wc->w_cpos,
&cluster_start, &cluster_end);
if ((wc->w_pos >> PAGE_CACHE_SHIFT) == page->index
&& !wc->w_finished_copy) {
wc->w_this_page = page;
wc->w_this_page_new = new;
ret = wc->w_write_data_page(inode, wc, p_blkno, &from, &to);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
copied = ret;
zero_from = from;
zero_to = to;
if (new) {
from = cluster_start;
to = cluster_end;
}
} else {
/*
* If we haven't allocated the new page yet, we
* shouldn't be writing it out without copying user
* data. This is likely a math error from the caller.
*/
BUG_ON(!new);
from = cluster_start;
to = cluster_end;
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end, 1);
if (ret) {
mlog_errno(ret);
goto out;
}
}
/*
* Parts of newly allocated pages need to be zero'd.
*
* Above, we have also rewritten 'to' and 'from' - as far as
* the rest of the function is concerned, the entire cluster
* range inside of a page needs to be written.
*
* We can skip this if the page is up to date - it's already
* been zero'd from being read in as a hole.
*/
if (new && !PageUptodate(page))
ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
wc->w_cpos, zero_from, zero_to);
flush_dcache_page(page);
if (ocfs2_should_order_data(inode)) {
ret = walk_page_buffers(handle,
page_buffers(page),
from, to, NULL,
ocfs2_journal_dirty_data);
if (ret < 0)
mlog_errno(ret);
}
/*
* We don't use generic_commit_write() because we need to
* handle our own i_size update.
*/
ret = block_commit_write(page, from, to);
if (ret)
mlog_errno(ret);
out:
return copied ? copied : ret;
}
/*
* Do the actual write of some data into an inode. Optionally allocate
* in order to fulfill the write.
*
* cpos is the logical cluster offset within the file to write at
*
* 'phys' is the physical mapping of that offset. a 'phys' value of
* zero indicates that allocation is required. In this case, data_ac
* and meta_ac should be valid (meta_ac can be null if metadata
* allocation isn't required).
*/
static ssize_t ocfs2_write(struct file *file, u32 phys, handle_t *handle,
struct buffer_head *di_bh,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc)
{
int ret, i, numpages = 1, new;
unsigned int copied = 0;
u32 tmp_pos;
u64 v_blkno, p_blkno;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
unsigned int cbits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
unsigned long index, start;
struct page **cpages;
new = phys == 0 ? 1 : 0;
/*
* Figure out how many pages we'll be manipulating here. For
* non-allocating write, or any writes where cluster size is
* less than page size, we only need one page. Otherwise,
* allocating writes of cluster size larger than page size
* need cluster size pages.
*/
if (new && !wc->w_large_pages)
numpages = (1 << cbits) / PAGE_SIZE;
cpages = kzalloc(sizeof(*cpages) * numpages, GFP_NOFS);
if (!cpages) {
ret = -ENOMEM;
mlog_errno(ret);
return ret;
}
/*
* Fill our page array first. That way we've grabbed enough so
* that we can zero and flush if we error after adding the
* extent.
*/
if (new) {
start = ocfs2_align_clusters_to_page_index(inode->i_sb,
wc->w_cpos);
v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, wc->w_cpos);
} else {
start = wc->w_pos >> PAGE_CACHE_SHIFT;
v_blkno = wc->w_pos >> inode->i_sb->s_blocksize_bits;
}
for(i = 0; i < numpages; i++) {
index = start + i;
cpages[i] = grab_cache_page(mapping, index);
if (!cpages[i]) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
}
if (new) {
/*
* This is safe to call with the page locks - it won't take
* any additional semaphores or cluster locks.
*/
tmp_pos = wc->w_cpos;
ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
&tmp_pos, 1, di_bh, handle,
data_ac, meta_ac, NULL);
/*
* This shouldn't happen because we must have already
* calculated the correct meta data allocation required. The
* internal tree allocation code should know how to increase
* transaction credits itself.
*
* If need be, we could handle -EAGAIN for a
* RESTART_TRANS here.
*/
mlog_bug_on_msg(ret == -EAGAIN,
"Inode %llu: EAGAIN return during allocation.\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL);
if (ret < 0) {
/*
* XXX: Should we go readonly here?
*/
mlog_errno(ret);
goto out;
}
BUG_ON(p_blkno == 0);
for(i = 0; i < numpages; i++) {
ret = ocfs2_write_data_page(inode, handle, &p_blkno, cpages[i],
wc, new);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
copied += ret;
}
out:
for(i = 0; i < numpages; i++) {
unlock_page(cpages[i]);
mark_page_accessed(cpages[i]);
page_cache_release(cpages[i]);
}
kfree(cpages);
return copied ? copied : ret;
}
static void ocfs2_write_ctxt_init(struct ocfs2_write_ctxt *wc,
struct ocfs2_super *osb, loff_t pos,
size_t count, ocfs2_page_writer *cb,
void *cb_priv)
{
wc->w_count = count;
wc->w_pos = pos;
wc->w_cpos = wc->w_pos >> osb->s_clustersize_bits;
wc->w_finished_copy = 0;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
wc->w_large_pages = 1;
else
wc->w_large_pages = 0;
wc->w_write_data_page = cb;
wc->w_private = cb_priv;
}
/*
* Write a cluster to an inode. The cluster may not be allocated yet,
* in which case it will be. This only exists for buffered writes -
* O_DIRECT takes a more "traditional" path through the kernel.
*
* The caller is responsible for incrementing pos, written counts, etc
*
* For file systems that don't support sparse files, pre-allocation
* and page zeroing up until cpos should be done prior to this
* function call.
*
* Callers should be holding i_sem, and the rw cluster lock.
*
* Returns the number of user bytes written, or less than zero for
* error.
*/
ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
size_t count, ocfs2_page_writer *actor,
void *priv)
{
int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
ssize_t written = 0;
u32 phys;
struct inode *inode = file->f_mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
struct ocfs2_alloc_context *data_ac = NULL;
struct ocfs2_alloc_context *meta_ac = NULL;
handle_t *handle;
struct ocfs2_write_ctxt wc;
ocfs2_write_ctxt_init(&wc, osb, pos, count, actor, priv);
ret = ocfs2_meta_lock(inode, &di_bh, 1);
if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
/*
* Take alloc sem here to prevent concurrent lookups. That way
* the mapping, zeroing and tree manipulation within
* ocfs2_write() will be safe against ->readpage(). This
* should also serve to lock out allocation from a shared
* writeable region.
*/
down_write(&OCFS2_I(inode)->ip_alloc_sem);
ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
/* phys == 0 means that allocation is required. */
if (phys == 0) {
ret = ocfs2_lock_allocators(inode, di, 1, &data_ac, &meta_ac);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1);
}
ret = ocfs2_data_lock(inode, 1);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out_data;
}
written = ocfs2_write(file, phys, handle, di_bh, data_ac,
meta_ac, &wc);
if (written < 0) {
ret = written;
mlog_errno(ret);
goto out_commit;
}
ret = ocfs2_journal_access(handle, inode, di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
pos += written;
if (pos > inode->i_size) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
}
inode->i_blocks = ocfs2_align_bytes_to_sectors((u64)(i_size_read(inode)));
di->i_size = cpu_to_le64((u64)i_size_read(inode));
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
ret = ocfs2_journal_dirty(handle, di_bh);
if (ret)
mlog_errno(ret);
out_commit:
ocfs2_commit_trans(osb, handle);
out_data:
ocfs2_data_unlock(inode, 1);
out_meta:
up_write(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_meta_unlock(inode, 1);
out:
brelse(di_bh);
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return written ? written : ret;
}
const struct address_space_operations ocfs2_aops = {
.readpage = ocfs2_readpage,
.writepage = ocfs2_writepage,

38
fs/ocfs2/aops.h
View file

@ -30,6 +30,44 @@ handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
unsigned from,
unsigned to);
struct ocfs2_write_ctxt;
typedef int (ocfs2_page_writer)(struct inode *, struct ocfs2_write_ctxt *,
u64 *, unsigned int *, unsigned int *);
ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
size_t count, ocfs2_page_writer *actor,
void *priv);
struct ocfs2_write_ctxt {
size_t w_count;
loff_t w_pos;
u32 w_cpos;
unsigned int w_finished_copy;
/* This is true if page_size > cluster_size */
unsigned int w_large_pages;
/* Filler callback and private data */
ocfs2_page_writer *w_write_data_page;
void *w_private;
/* Only valid for the filler callback */
struct page *w_this_page;
unsigned int w_this_page_new;
};
struct ocfs2_buffered_write_priv {
char *b_src_buf;
const struct iovec *b_cur_iov; /* Current iovec */
size_t b_cur_off; /* Offset in the
* current iovec */
};
int ocfs2_map_and_write_user_data(struct inode *inode,
struct ocfs2_write_ctxt *wc,
u64 *p_blkno,
unsigned int *ret_from,
unsigned int *ret_to);
/* all ocfs2_dio_end_io()'s fault */
#define ocfs2_iocb_is_rw_locked(iocb) \
test_bit(0, (unsigned long *)&iocb->private)

4
fs/ocfs2/extent_map.c
View file

@ -67,8 +67,8 @@ static int ocfs2_search_extent_list(struct ocfs2_extent_list *el,
return ret;
}
static int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
u32 *p_cluster, u32 *num_clusters)
int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
u32 *p_cluster, u32 *num_clusters)
{
int ret, i;
struct buffer_head *di_bh = NULL;

2
fs/ocfs2/extent_map.h
View file

@ -25,6 +25,8 @@
#ifndef _EXTENT_MAP_H
#define _EXTENT_MAP_H
int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
u32 *num_clusters);
int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
int *ret_count);

376
fs/ocfs2/file.c
View file

@ -33,6 +33,7 @@
#include <linux/sched.h>
#include <linux/pipe_fs_i.h>
#include <linux/mount.h>
#include <linux/writeback.h>
#define MLOG_MASK_PREFIX ML_INODE
#include <cluster/masklog.h>
@ -485,13 +486,13 @@ leave:
* accessed, and lock them, reserving the appropriate number of bits.
*
* Called from ocfs2_extend_allocation() for file systems which don't
* support holes, and from ocfs2_prepare_write() for file systems
* which understand sparse inodes.
* support holes, and from ocfs2_write() for file systems which
* understand sparse inodes.
*/
static int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
u32 clusters_to_add,
struct ocfs2_alloc_context **data_ac,
struct ocfs2_alloc_context **meta_ac)
int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
u32 clusters_to_add,
struct ocfs2_alloc_context **data_ac,
struct ocfs2_alloc_context **meta_ac)
{
int ret, num_free_extents;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@ -518,7 +519,7 @@ static int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
* a cluster lock (because we ran out of room for another
* extent) will violate ordering rules.
*
* Most of the time we'll only be seeing this 1 page at a time
* Most of the time we'll only be seeing this 1 cluster at a time
* anyway.
*/
if (!num_free_extents ||
@ -596,13 +597,6 @@ static int ocfs2_extend_allocation(struct inode *inode,
restart_all:
BUG_ON(le32_to_cpu(fe->i_clusters) != OCFS2_I(inode)->ip_clusters);
status = ocfs2_lock_allocators(inode, fe, clusters_to_add, &data_ac,
&meta_ac);
if (status) {
mlog_errno(status);
goto leave;
}
/* blocks peope in read/write from reading our allocation
* until we're done changing it. We depend on i_mutex to block
* other extend/truncate calls while we're here. Ordering wrt
@ -610,6 +604,13 @@ restart_all:
down_write(&OCFS2_I(inode)->ip_alloc_sem);
drop_alloc_sem = 1;
status = ocfs2_lock_allocators(inode, fe, clusters_to_add, &data_ac,
&meta_ac);
if (status) {
mlog_errno(status);
goto leave;
}
credits = ocfs2_calc_extend_credits(osb->sb, fe, clusters_to_add);
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
@ -1088,10 +1089,49 @@ out:
return ret;
}
/*
* Will look for holes and unwritten extents in the range starting at
* pos for count bytes (inclusive).
*/
static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos,
size_t count)
{
int ret = 0;
unsigned int extent_flags;
u32 cpos, clusters, extent_len, phys_cpos;
struct super_block *sb = inode->i_sb;
cpos = pos >> OCFS2_SB(sb)->s_clustersize_bits;
clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
while (clusters) {
ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
&extent_flags);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
ret = 1;
break;
}
if (extent_len > clusters)
extent_len = clusters;
clusters -= extent_len;
cpos += extent_len;
}
out:
return ret;
}
static int ocfs2_prepare_inode_for_write(struct dentry *dentry,
loff_t *ppos,
size_t count,
int appending)
int appending,
int *direct_io)
{
int ret = 0, meta_level = appending;
struct inode *inode = dentry->d_inode;
@ -1143,12 +1183,47 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry,
saved_pos = *ppos;
}
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
loff_t end = saved_pos + count;
/*
* Skip the O_DIRECT checks if we don't need
* them.
*/
if (!direct_io || !(*direct_io))
break;
/*
* Allowing concurrent direct writes means
* i_size changes wouldn't be synchronized, so
* one node could wind up truncating another
* nodes writes.
*/
if (end > i_size_read(inode)) {
*direct_io = 0;
break;
}
/*
* We don't fill holes during direct io, so
* check for them here. If any are found, the
* caller will have to retake some cluster
* locks and initiate the io as buffered.
*/
ret = ocfs2_check_range_for_holes(inode, saved_pos,
count);
if (ret == 1) {
*direct_io = 0;
ret = 0;
} else if (ret < 0)
mlog_errno(ret);
break;
}
/*
* The rest of this loop is concerned with legacy file
* systems which don't support sparse files.
*/
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
break;
newsize = count + saved_pos;
@ -1202,55 +1277,264 @@ out:
return ret;
}
static inline void
ocfs2_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
{
const struct iovec *iov = *iovp;
size_t base = *basep;
do {
int copy = min(bytes, iov->iov_len - base);
bytes -= copy;
base += copy;
if (iov->iov_len == base) {
iov++;
base = 0;
}
} while (bytes);
*iovp = iov;
*basep = base;
}
static struct page * ocfs2_get_write_source(struct ocfs2_buffered_write_priv *bp,
const struct iovec *cur_iov,
size_t iov_offset)
{
int ret;
char *buf;
struct page *src_page = NULL;
buf = cur_iov->iov_base + iov_offset;
if (!segment_eq(get_fs(), KERNEL_DS)) {
/*
* Pull in the user page. We want to do this outside
* of the meta data locks in order to preserve locking
* order in case of page fault.
*/
ret = get_user_pages(current, current->mm,
(unsigned long)buf & PAGE_CACHE_MASK, 1,
0, 0, &src_page, NULL);
if (ret == 1)
bp->b_src_buf = kmap(src_page);
else
src_page = ERR_PTR(-EFAULT);
} else {
bp->b_src_buf = buf;
}
return src_page;
}
static void ocfs2_put_write_source(struct ocfs2_buffered_write_priv *bp,
struct page *page)
{
if (page) {
kunmap(page);
page_cache_release(page);
}
}
static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
const struct iovec *iov,
unsigned long nr_segs,
size_t count,
ssize_t o_direct_written)
{
int ret = 0;
ssize_t copied, total = 0;
size_t iov_offset = 0;
const struct iovec *cur_iov = iov;
struct ocfs2_buffered_write_priv bp;
struct page *page;
/*
* handle partial DIO write. Adjust cur_iov if needed.
*/
ocfs2_set_next_iovec(&cur_iov, &iov_offset, o_direct_written);
do {
bp.b_cur_off = iov_offset;
bp.b_cur_iov = cur_iov;
page = ocfs2_get_write_source(&bp, cur_iov, iov_offset);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
goto out;
}
copied = ocfs2_buffered_write_cluster(file, *ppos, count,
ocfs2_map_and_write_user_data,
&bp);
ocfs2_put_write_source(&bp, page);
if (copied < 0) {
mlog_errno(copied);
ret = copied;
goto out;
}
total += copied;
*ppos = *ppos + copied;
count -= copied;
ocfs2_set_next_iovec(&cur_iov, &iov_offset, copied);
} while(count);
out:
return total ? total : ret;
}
static int ocfs2_check_iovec(const struct iovec *iov, size_t *counted,
unsigned long *nr_segs)
{
size_t ocount; /* original count */
unsigned long seg;
ocount = 0;
for (seg = 0; seg < *nr_segs; seg++) {
const struct iovec *iv = &iov[seg];
/*
* If any segment has a negative length, or the cumulative
* length ever wraps negative then return -EINVAL.
*/
ocount += iv->iov_len;
if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
return -EINVAL;
if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
continue;
if (seg == 0)
return -EFAULT;
*nr_segs = seg;
ocount -= iv->iov_len; /* This segment is no good */
break;
}
*counted = ocount;
return 0;
}
static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
const struct iovec *iov,
unsigned long nr_segs,
loff_t pos)
{
int ret, rw_level, have_alloc_sem = 0;
struct file *filp = iocb->ki_filp;
struct inode *inode = filp->f_path.dentry->d_inode;
int appending = filp->f_flags & O_APPEND ? 1 : 0;
int ret, direct_io, appending, rw_level, have_alloc_sem = 0;
int can_do_direct, sync = 0;
ssize_t written = 0;
size_t ocount; /* original count */
size_t count; /* after file limit checks */
loff_t *ppos = &iocb->ki_pos;
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode;
mlog_entry("(0x%p, %u, '%.*s')\n", filp,
mlog_entry("(0x%p, %u, '%.*s')\n", file,
(unsigned int)nr_segs,
filp->f_path.dentry->d_name.len,
filp->f_path.dentry->d_name.name);
file->f_path.dentry->d_name.len,
file->f_path.dentry->d_name.name);
/* happy write of zero bytes */
if (iocb->ki_left == 0)
return 0;
ret = ocfs2_check_iovec(iov, &ocount, &nr_segs);
if (ret)
return ret;
count = ocount;
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
appending = file->f_flags & O_APPEND ? 1 : 0;
direct_io = file->f_flags & O_DIRECT ? 1 : 0;
mutex_lock(&inode->i_mutex);
relock:
/* to match setattr's i_mutex -> i_alloc_sem -> rw_lock ordering */
if (filp->f_flags & O_DIRECT) {
have_alloc_sem = 1;
if (direct_io) {
down_read(&inode->i_alloc_sem);
have_alloc_sem = 1;
}
/* concurrent O_DIRECT writes are allowed */
rw_level = (filp->f_flags & O_DIRECT) ? 0 : 1;
rw_level = !direct_io;
ret = ocfs2_rw_lock(inode, rw_level);
if (ret < 0) {
rw_level = -1;
mlog_errno(ret);
goto out_sems;
}
can_do_direct = direct_io;
ret = ocfs2_prepare_inode_for_write(file->f_path.dentry, ppos,
iocb->ki_left, appending,
&can_do_direct);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_prepare_inode_for_write(filp->f_path.dentry, &iocb->ki_pos,
iocb->ki_left, appending);
if (ret < 0) {
mlog_errno(ret);
goto out;
/*
* We can't complete the direct I/O as requested, fall back to
* buffered I/O.
*/
if (direct_io && !can_do_direct) {
ocfs2_rw_unlock(inode, rw_level);
up_read(&inode->i_alloc_sem);
have_alloc_sem = 0;
rw_level = -1;
direct_io = 0;
sync = 1;
goto relock;
}
if (!sync && ((file->f_flags & O_SYNC) || IS_SYNC(inode)))
sync = 1;
/*
* XXX: Is it ok to execute these checks a second time?
*/
ret = generic_write_checks(file, ppos, &count, S_ISBLK(inode->i_mode));
if (ret)
goto out;
/*
* Set pos so that sync_page_range_nolock() below understands
* where to start from. We might've moved it around via the
* calls above. The range we want to actually sync starts from
* *ppos here.
*
*/
pos = *ppos;
/* communicate with ocfs2_dio_end_io */
ocfs2_iocb_set_rw_locked(iocb);
ret = generic_file_aio_write_nolock(iocb, iov, nr_segs, iocb->ki_pos);
if (direct_io) {
written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
ppos, count, ocount);
if (written < 0) {
ret = written;
goto out_dio;
}
} else {
written = ocfs2_file_buffered_write(file, ppos, iov, nr_segs,
count, written);
if (written < 0) {
ret = written;
if (ret != -EFAULT || ret != -ENOSPC)
mlog_errno(ret);
goto out;
}
}
out_dio:
/* buffered aio wouldn't have proper lock coverage today */
BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));
/*
* deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
@ -1268,14 +1552,25 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
}
out:
if (have_alloc_sem)
up_read(&inode->i_alloc_sem);
if (rw_level != -1)
ocfs2_rw_unlock(inode, rw_level);
out_sems:
if (have_alloc_sem)
up_read(&inode->i_alloc_sem);
if (written > 0 && sync) {
ssize_t err;
err = sync_page_range_nolock(inode, file->f_mapping, pos, count);
if (err < 0)
written = err;
}
mutex_unlock(&inode->i_mutex);
mlog_exit(ret);
return ret;
return written ? written : ret;
}
static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
@ -1300,7 +1595,8 @@ static ssize_t ocfs2_file_splice_write(struct pipe_inode_info *pipe,
goto out;
}
ret = ocfs2_prepare_inode_for_write(out->f_path.dentry, ppos, len, 0);
ret = ocfs2_prepare_inode_for_write(out->f_path.dentry, ppos, len, 0,
NULL);
if (ret < 0) {
mlog_errno(ret);
goto out_unlock;

4
fs/ocfs2/file.h
View file

@ -46,6 +46,10 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
enum ocfs2_alloc_restarted *reason);
int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
u32 clusters_to_add,
struct ocfs2_alloc_context **data_ac,
struct ocfs2_alloc_context **meta_ac);
int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);
int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat);

32
fs/ocfs2/ocfs2.h
View file

@ -463,6 +463,38 @@ static inline unsigned long ocfs2_align_bytes_to_sectors(u64 bytes)
return (unsigned long)((bytes + 511) >> 9);
}
static inline unsigned int ocfs2_page_index_to_clusters(struct super_block *sb,
unsigned long pg_index)
{
u32 clusters = pg_index;
unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
if (unlikely(PAGE_CACHE_SHIFT > cbits))
clusters = pg_index << (PAGE_CACHE_SHIFT - cbits);
else if (PAGE_CACHE_SHIFT < cbits)
clusters = pg_index >> (cbits - PAGE_CACHE_SHIFT);
return clusters;
}
/*
* Find the 1st page index which covers the given clusters.
*/
static inline unsigned long ocfs2_align_clusters_to_page_index(struct super_block *sb,
u32 clusters)
{
unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
unsigned long index = clusters;
if (PAGE_CACHE_SHIFT > cbits) {
index = clusters >> (PAGE_CACHE_SHIFT - cbits);
} else if (PAGE_CACHE_SHIFT < cbits) {
index = clusters << (cbits - PAGE_CACHE_SHIFT);
}
return index;
}
#define ocfs2_set_bit ext2_set_bit
#define ocfs2_clear_bit ext2_clear_bit
#define ocfs2_test_bit ext2_test_bit